If the smallest transition bandwidth is
Hz, then the FFT size
should satisfy
. Otherwise, there may be too much time
aliasing in the desired impulse response.5.10 The only non-obvious
part in the matlab below is ``.^8'' which smooths the taper to
zero and looks better on a log magnitude scale. It would also make
sense to do a linear taper on a dB scale which corresponds to
an exponential taper to zero.